本論文主要目的在模擬聽覺的生理現象―遮蔽效應及反遮蔽效應，遮蔽效應及反遮蔽效應對人耳的幫助甚大，遮蔽效應及反遮蔽效應都可以藉由內側橄欖耳蝸中繼神經元(Medial Olivocochlear,MOC)對外毛細胞產生影響所造成，MOC有一條負迴授連接至外毛細胞，當基膜上的振幅過大使得聲音強度增強到可能損害聽力系統時，MOC會做出抑制，讓外毛細胞之電動性便因此降低，基膜的振動程度也因此變小，造成聽神經產生的動作電位次數降低，以達到保護聽力的作用，此為遮蔽效應的功能；至於反遮蔽效應則為在有噪音的環境中，當有MOC抑制的情況下，可對噪音產生較大抑制而對語音訊號產生較少抑制，因此即使在有噪音的影響下，還是能透過此機制的作用，使接收到的訊號更加清晰，這種現象稱為反遮蔽效應。模擬所利用之聽覺迴路模型以Liu and Neely (2009)(2010)所提出的中耳至內耳耳蝸模型為基礎，再連接多個聽覺生理模型，形成一聽覺迴路模型，並期望透過此模型調整模型參數來模擬經過MOC之聽覺反射對基膜上行進波的影響，以及受到MOC影響後的聽神經觸發次數的變化，以期望在聽力診斷與聽覺心理學(psychoacoustics）上有所貢獻。

The main purpose of this thesis is to simulate human’s ear hearing physiological phenomena-the masking effect and unmasking effect. Both of these two are helpful for our ears, which are able to use the medial olivocochlear(Medial Olivocochlear, MOC) to affect outer hair cells. MOC has a negative feedback which connects to outer hearing cells. Our hearing system might be damaged when the amplitude on the Basilar Membrane is too large. Hence, the MOC will suppress it and the motility of outer hearing cells would be reduced so that the vibration of Basilar Membrane would also calm down. This results in decreasing the number of the action potentials made by our hearing nerves. In this way we are able to protect our hearing system. The mentioned above is so-called masking effect.On the other hand, as for the unmasking effect, while we are exposed to the noisy environment, we can have more suppression for the noise and the less suppression for the letters if we get the MOC. As a result, even if we are in a noisy place, we can still use this to make the letter we received much clearer, and that is unmasking effect.This researching model is based on the middle ear to the cochlea, which was referred by Liu and Neely(2009)(2010), and then it combines with a variety of models for our physiological hearing, eventually leads to a hearing pathway model.Right now we are looking forward to using this model (change some parameters if needed) to simulate the effect of Basilar Membrane by using MOC, and then we see the situation of the hearing nerves effected by MOC. Hopefully, we expect to give some devoting to the hearing diagnosis and the psychoacoustics.

1. 余律明."建立中耳至腦幹之聽覺生理模型並利用特定頻率延遲之tuberculoventral抑制模擬耳蝸反遮蔽效應"國立清華大學碩士研究論文(2012).
2. Willert, V., et al. (2006). "A probabilistic model for binaural sound localization." IeeeTransactions on Systems Man and Cybernetics Part B-Cybernetics 36(5): 982-994.
3. J. F. Stein with C. J. Stoodley. Neuroscience: an introduction, 3rd edition, Wiley & Sons, 2006.
4. Squire, L. R. (2008). Fundamental neuroscience. Amsterdam ; Boston, Elsevier / Academic Press.
5. Guinan, J. J., Jr. (2006). "Olivocochlearefferents: anatomy, physiology, function, and the measurement of efferent effects in humans." Ear Hear27(6): 589-607.
6. Von Békésy , G. (1960). Experiments in hearing. New York,, McGraw-Hill.
7. J.G.Roederer.(1995) "The physics and psychophysics of music."Springer-Verlag.
8. Raphael, Y. and R. A. Altschuler (2003). "Structure and innervations of the cochlea. "Brain Res Bull60(5-6): 397-422.
9. Stankovic, K., et al. (2004). "Survival of adult spiral ganglion neurons requires erbB receptor signaling in the inner ear." Journal of Neuroscience24(40): 8651-8661.
10. Dallos, P. (2008). "Cochlear amplification, outer hair cells and prestin." Current Opinion in Neurobiology18(4): 370-376.
11. Meddis, R. (1986). "Simulation of Mechanical to Neural Transduction in the Auditory Receptor." Journal of the Acoustical Society of America79(3):702-711.
12. Moser, T., A. Brandt, et al.(2006). "Hair cell ribbon synapses. "Cell Tissue Res326(2): 347-359.
13. Sumner, C. J., et al. (2002). "A revised model of the inner-hair cell and auditory-nerve complex." Journal of the Acoustical Society of America111(5): 2178-2188.
14. Young, E. D. and D. Oertel (2004). Chap. 4 The cochlear nucleus. In Shepherd, G. M., The synaptic organization of the brain(pp.125-171).Oxford ; New York,Oxford University Press.
15. A. van Schaik, E. Fragniere and E. Vittoz.(1996). "An analogue electronic modelof ventral cochlear nucleus neurons,"IEEE Int. Conf. Microelectronics for Neural Networks, pp.52-59.
16. Guinan J.J. (2011).Chap.3 physiology of the Medial and Lateral OlivocochlearSystems.In Ryugo,D.K.,R.R.Fay,etal.Auditory and vestibular efferents(pp39-81).New York,Springer.
17. Liu, Y. W. and S. T. Neely (2009). "Outer hair cell electromechanical properties in a nonlinear piezoelectric model." Journal of the Acoustical Society of America126(2): 751-761.
18. Liu, Y. W. and S. T. Neely (2010). "Distortion product emissions from a cochlear model with nonlinear mechanoelectrical transduction in outer hair cells." Journal of the Acoustical Society of America127(4): 2420-2432.
19. Shera, C. A. (2007). "Laser amplification with a twist: Traveling-wave propagation and gain functions from throughout the cochlea." Journal of the Acoustical Society of America122(5): 2738-2758.
20. Hudspeth, A. J. (1997). "Mechanical amplification of stimuli by hair cells."Current Opinion in Neurobiology7(4): 480-486.
21. Brownell, W. E., et al. (1985). "Evoked Mechanical Responses of Isolated Cochlear Outer Hair-Cells." Science227(4683): 194-196.
22. Ashmore, J. F. (1987). "A Fast Motile Response in Guinea-Pig Outer Hair-Cells - the Cellular Basis of the Cochlear Amplifier." Journal of Physiology-London388: 323-347.
23. Matthews, J. W. (1983). "Modeling reverse middle ear transmission of acoustic distortion signals, " in Mechanics of Hearing, edited by E. de Boer and M. A. Viergever Delft University Press, Delft_, pp. 11-18.
24. Zwisolocki, J. (1962). "Analysis of the middle-ear function. Part I:Input impedance, " J. Acoust. Soc. Am. 34, 1514-1523.
25. Santos-Sacchi, J. (1991). "Reversible inhibition of voltage-dependent outer hair cell motility and capacitance. " J Neurosci11(10): 3096-3110.
26. Scherer, M. P. and A. W. Gummer (2004). "Vibration pattern of the organ of Corti up to 50 kHz: evidence for resonant electromechanical force. "ProcNatlAcadSci U S A101(51): 17652-17657.
27. Dallos, P. (1973). The auditory periphery; biophysics and physiology. New York,, Academic Press.
28. M. B. Sachs and P. J. Abbas (1974)."Rate versus level function for auditory-nervefibers in cats:tone-burst stimuli,” J AcoustSoc Am56:1835-1847.
29. de Boer, E. and H. R. de Jongh (1978). "On cochlear encoding: potentialities and limitations of the reverse-correlation technique."Journal of the Acoustical Society of America63(1):115-135.
30. Carney, L. H. and T. C. Yin (1988). "Temporal coding of resonances by low-frequency auditory nerve fibers: single-fiber responses and a population model. " JNeurophysiol60 (5):1653-1677.
31. Shamma, S. A., R. S. Chadwick, et al. (1986). "A biophysical model of cochlear processing: intensity dependence of pure tone responses. "J AcoustSocAm80(1): 133-145.
32. Mountain D. C., and Hubbard, A. E. (1996). "Computational analysis of hair cell and auditory nerve process, " in Auditory Computation edited by H. L. Hawkins, T. A. McMullen, A. N. Popper, and R. R. Fay (Springer, New York).
33. Russell, I. J., A. R. Cody, et al. (1986)." The Responses of Inner and Outer Hair-Cells in the Basal Turn of the Guinea-Pig Cochlea and in the Mouse Cochlea Grown-Invitro. "Hear Res22(1-3): 199-216.
34. Hudspeth, A. J. and R. S. Lewis (1988). "Kinetic-Analysis of Voltage-Dependent and Ion-Dependent Conductances in Saccular Hair-Cells of the Bull-Frog, Rana-Catesbeiana. "Journal of Physiology-London 400: 237-274.
35. Kidd, R. C., and Weiss, T. F. (1990). "Mechanism that degrade timimg information in the cochlea, " Hear. Res. 49, 181-208.
36. Johnston, D. and S. M.-s. Wu (1995). Foundations of cellular neurophysiology. Cambridge, Mass., MIT Press.
37. Dayan, P. and L. F. Abbott (2001). Theoretical neuroscience: computational and mathematical modeling of neural systems. Cambridge, Mass., Massachusetts Institute of Technology Press.
38. W. S. Rhode and S. Greenberg (1992). "Physiology of theCochlear Nuclei," in The Mammalian Auditory Pathway: Neurophysiology, Edited by Popper, A.N., and Fay, R.R., Springer-Verlag, New York.
39. M. C. Brown, R. K. de Venecia, J. J. Guinan, Jr.(2003)."Responses of medial olivocochlear neurons: specifying the central pathways of the MOC reflex."Exp
Brain Res153(4): 491-498.
40. Guinan, J. J. and M. L. Gifford (1988). "Effects of Electrical-Stimulation of Efferent Olivocochlear Neurons on Cat Auditory-Nerve Fibers .1. Rate-Level Functions." Hearing Research33(2): 97-113.
41. Guinan, J. J. and K. M. Stankovic (1996). "Medial efferent inhibition produces the largest equivalent attenuations at moderate to high sound levels in cat auditory-nerve fibers." Journal of the Acoustical Society of America100(3): 1680-1690.
42. Kawase, T., et al. (1993). "Antimasking Effects of the Olivocochlear Reflex .2. Enhancement of Auditory-Nerve Response to Masked Tones." Journal of Neurophysiology70(6): 2533-2549.